I will be contributing some new work at soon at Unisolve which will revolve around HTML::Mason and the Yahoo! User Interface Library (YUI). I am really looking forward to digging further into these tools.
Mason is a templating engine for Perl programmers. That means that you can mix Perl code with your data (often HTML) so that additional content can be generated in the fly before the information is presented. For instance you can extract records from a database. There are a plethora of these tools, however Mason is one of the more established.